Duke Energy defends its 'coal ash' record

Thursday

Jan 10, 2013 at 12:01 AMJan 10, 2013 at 3:21 PM

Amanda Memrick

Riverbend Steam Station north of Mount Holly operates infrequently, and Allen Steam Station south of Belmont runs during seasonal peaks, said Tim Gause, Duke Energy region director of government and community relations. The Allen plant is projected to run less as natural gas becomes a more prevalent source of energy at a low price, he said.

Coal ash concerns

“I know there have been some questions or concern about the safety of coal ash dams,” Gause said. “You need to know that we have been inspecting these facilities with a formal program since the 1970s. We have a satisfactory rating as given to us by the EPA. Satisfactory is the highest of the four ratings that the EPA will give a utility company on their ash basins.”

Both Riverbend and Allen plants have a “high hazard” rating by the EPA. Gause said the high hazard rating is not related to the structural integrity but to the plant’s proximity to large population centers.

A high hazard rating means a dam failure would likely cause loss of human life.

The Catawba Riverkeeper Foundation recently discovered places where coal ash ponds were leaking. Gause said seepage is a normal function that happens with a healthy engineered dam.

“Duke Energy and regulators have identified or reviewed the seeps that were identified by the Riverkeeper and found nothing of concern to dam safety or water quality,” Gause said. “The amount of water lost through seepage is minute.”

TheRiverbend Steam Station and the Allen Steam Station have unlined coal ash ponds.Allen Steam Station has converted to dry fly ash, which isn’t stored in coal ash basins but is handled in a landfill with a synthetic liner to prevent leaching. Riverbend Steam Station is slated to close in 2015. Duke Energy will continue monitoring the Riverbend site after it closes, Gause said.

Duke Energy’s water sampling upstream and downstream from its power plants found water quality remains good, Gause said. The trace metals detected were below levels allowed by the state.

“The drinking water and the aquatic life are safe,” Gause said.

Drinking water

Catawba Riverkeeper Rick Gaskins listened to Gause’s presentation Monday and said Duke Energy may have created a false sense of security with its carefully chosen words.

Gause said that the amount of water leaking out of coal ash ponds was 28,000 times less than what’s permitted at outfalls, where water used in the coal plants are released back into the river.

“I think their main argument on the seeps is, ‘Well, it’s a small amount relative to the total discharge.’ When you look at that total discharge, it’s in some cases billions of gallons a day,” Gaskins said. “When you’re talking about something going into drinking water, it’s still a lot.”

The Riverkeeper isn’t saying the water isn’t safe to drink now, but that problems may happen down the road as more contaminants and minerals build up in the sediment.

Duke Energy’s average numbers showed low levels of minerals and trace elements, but those numbers don’t show the periodic spikes that happen when conditions change, such as when water levels drop during a drought, Gaskins said.

Gaskins said he requested to speak before Belmont City Council during its next monthly meeting to present the Riverkeeper’s view.

“Why would you take the chance to allow people to discharge toxic materials into the drinking water?” Gaskins asked.

You can reach reporter Amanda Memrick at 704-869-1839 and follow @AmandaMemrick on Twitter.

What is coal ash?

Coal ash is produced when coal is burned at power plants. Coal ash contains contaminants like mercury, cadmium and arsenic in addition to minerals like silicon, aluminum, iron and calcium. According to the EPA, those contaminants can leach into groundwater and drinking water sources and pose significant health concerns if proper protections are not taken.